Avalanche Forecast

An upper level weather disturbance should bring generally light to locally moderate new snow Sunday night through the first half of Monday followed by scattered afternoon/evening showers. Due to a fair amount of uncertainty with the weather forecast, a moderate hazard rating will be maintained near and above treeline across the Cascades for new storm snow problems. In areas that receive little new snowfall through Monday afternoon... expect a lower avalanche danger than the regional forecast. 

Shallow storm slabs may develop Monday with new snow bonding poorly to aspects with surface crusts. It's April, so be aware of increased solar input reaching more aspects and affecting the snow surface more quickly than winter-time. Loose wet avalanches involving recent storm snow will be possible as well Monday, especially if there are sunbreaks in the afternoon. 

Small loose dry avalanches are also possible on non-solar aspects at higher elevations. Loose dry avalanches won't be listed as a top avalanche problem, but be aware of fast moving sluffs knocking you off your feet and into unintended terrain traps on steeper slopes. 

Due to the continued cool weather, cornices won't be listed as an avalanche problem either but use caution on slopes below cornices and on ridges where it can be hard to know if a cornice is present.

The recent active weather since about mid March onward has brought periodic light snowfalls east of the crest and allowed general snowpack consolidation and stabilization. 

During the fair and mild weather Monday Mar 30th, DOT avalanche professionals working in the Washington Pass area triggered slides using explosives. Wet slab avalanches entrained moist snow in the Liberty Bell paths and buried the closed highway with about 8 ft of debris. Little natural avalanche activity was observed in the area during this time period. 

A front moved across the Northwest Tuesday followed by showers and rapid cooling but caused little snow east of the crest expect locally downwind of a convergence zone centered on Snoqualmie Pass.

A TAY report from Mt. Stuart Thursday reported 6-12" of unconsolidated snow even on solar aspects above treeline, likely a benefactor of Tuesday night's convergence zone. NWAC observer Jeremy Allyn was at Washington Pass on Friday and found about an inch of recent snow on a thick crust that needed additional loading to become problematic, however about an inch or less fell Friday night along the east slopes. 

Snowdepths vary greatly across the east slopes with a regionally healthy snowpack in the northeast Cascades to bare solar and lower elevation slopes in the central and southeast Cascades. Many areas at lower elevations and further away from the Cascade crest do not have enough snow to cause an avalanche danger.